Giffen specialises in mechanical, electrical and power services within the railway sector and works for​ ​Network Rail​, ​London Underground and a number of train ​o​perating ​​companies.

It has four frameworks with Network Rail and six frameworks with London Underground.

​"Giffen has built a reputation in the rail sector," said Mr Scott.

"It would have been extremely difficult for us to grow our business with London Underground as we don't do any work with them at the moment so this is a new opportunity.

"London Underground is spending £2.4bn per annum to renew its entire network and one of our ambitions is to cross sell to London Underground."

He said that the group is looking at other acquisitions.

"We are looking at one in infrastructure and one in environmental. They went away to reshape what they are presenting."

Renew said it had not been impacted by the UK's decision to leave the EU.

"We've seen no Brexit impact," said Mr Scott.

"UK infrastructure is a pretty good place to be. There is not an option to slow down. We are not exposed to volatility.

"We are looking to the future with confidence and we have long term visibility."

Analyst Howard Seymour at Numis said: "In keeping with previous years, we have seen and continue to expect a solid market backdrop for Renew, organic out performance (both against the market and management's latest targets) and strengthening balance sheet which will enable complementary growth through acquisition.

"Renew offers a unique mix of growth plus defensive attributes in these uncertain times which are not factored into the share price in our view, hence our increased target price here and 'Add' recommendation."